MEXICO CITY — Mexican officials expressed doubt Thursday that any children — dead or alive — remained in the rubble of a collapsed elementary school in Mexico City, an outcome that could turn into an emotional whipsaw for a country that had been fixated for nearly 24 hours on the search for a missing student following a devastating earthquake.

Authorities have confirmed 25 dead — 19 children and six adults — at the school, and they said that 11 other children were treated at hospitals for non-life-threatening injuries. While search teams identified an adult woman trapped in the rubble, who may have died, they said they suspected that no one else would be found in the wreckage, as all students were accounted for.

“It is very likely that there is nobody,” a senior Mexican official said at the site, while insisting that the search would continue until any shred of doubt was removed. Another official, Adm. Angel Enrique Sarmiento, deputy secretary of the Mexican navy, told reporters that “we are sure that all the children either unfortunately died or are in hospitals or safe in their homes.”

The prospect that no more students would be found could become an embarrassment for the Mexican government as the story of “Frida Sofia,” a 12-year-old girl reportedly trapped in the debris, has burgeoned into a media sensation.

The school had emerged as a symbol of the horror and heartbreak caused by Tuesday’s 7.1-magnitude earthquake, which has left at least 273 people dead and more than 2,000 injured in the capital and five states. The highest number of fatalities — 137 — was in Mexico City. The quake occurred on the 32nd anniversary of the disastrous temblor that demolished parts of the capital in 1985 and left thousands dead.

On the third day of the rescue effort, hopes were dwindling that victims in other parts of the city or surrounding states might be saved. But emergency workers and volunteers continued to frantically dig in the rubble of shattered buildings, using dogs, cameras and motion-sensing equipment. Several people were pulled from demolished buildings late Wednesday and early Thursday.

Reuters quoted Taiwan’s foreign ministry as saying that five of its citizens were trapped in a clothing factory that had crumbled in the capital’s central Obrera neighborhood. Volunteers were searching the rubble at the factory when they heard signs of life, the agency said.

Rescue teams streamed into Mexico from other countries, including the Los Angeles County Fire Department’s search-and-rescue squad.

Dozens of buildings toppled in the capital after it was hit by the quake, whose epicenter was to the southeast in the state of Puebla. Tragic stories emerged of lives lost, including 11 family members who died at a child’s baptism in the state of Puebla when a church caved in. The victims included the infant.

But the drama that captured the greatest national attention played out at the partially destroyed Colegio Enrique Rebsamen, a private elementary school with about 400 students in southern Mexico City.

It was not immediately clear how the story originated that a girl remained buried inside the school. However it began, round-the-clock media coverage of the rescue operation riveted the Mexican public, with a bank of cameras filming live every poke and prod and puzzled look of the security forces and emergency workers who were searching the rubble. Senior Mexican officials, including Education Secretary Aurelio Nuño, spent hours at the school watching the effort.

The operation struck some observers as an attempt to portray Mexican officials as lifesaving heroes.

“This is just like Mexican politics, incredible,” said Edgar Felix, a freelance reporter for several Mexican outlets who had just spent more than 30 hours without sleep watching the rescue effort from inside the school courtyard. “This was just a media spectacle.”

The senior Mexican official, who spoke on the condition of anonymity since he was not authorized to talk to the media, said a decision now must be made about whether to resort to demolition equipment to take down the building more quickly.

Despite official doubts that emerged Wednesday evening about the reports of a trapped girl, workers painstakingly probed the collapsed wing of the three-story school for survivors into Thursday afternoon.

At times, workers on the roof would lower microphones or other sensors into the rubble to try to detect any human sounds. Ataround 1 p.m. Thursday, the leader of the effort called out “Negative!” from the roof, suggesting that the rescuers had not heard what they were listening for. Not long after that, senior government officials began to slip away from the scene.

From the command center on the roof, a military officer called out for members of the military to evacuate. But other rescue workers remained on the scene, continuing the search.

On Wednesday night, Televisa reporter Danielle Dithurbide had said she was told by the navy admiral leading the recovery effort that “Frida Sofia” was able to tell rescuers that five other students were possibly trapped with her.

Officials overseeing the search now believe that nobody named “Frida Sofia” attended the school. The family of the only Frida who is enrolled was contacted, and were found to be “pleasantly asleep with the girl” at home, according to the senior Mexican official.

Mexico City began to resume some semblance of normality on Thursday, with power restored to 95 percent of the population, according to President Enrique Peña Nieto. There has been a massive outpouring of assistance for earthquake victims, with citizens donating food, water and blankets.

Officials in other parts of the country began to tally estimates of the huge damage caused by the quake. Governor Jose Antonio Gali of Puebla said that 86 churches in the state had sustained damage and more than 1,600 homes were so battered they would have to be demolished.

Gabriela Martinez in Mexico City and William Branigin in Washington contributed to this report.